1921281 has 8 divisors (see below), whose sum is σ = 2578080. Its totient is φ = 1272672.

The previous prime is 1921277. The next prime is 1921307. The reversal of 1921281 is 1821291.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1921281 - 2² = 1921277 is a prime.

It is a super-2 number, since 2×1921281² = 7382641361922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1921211) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1476 + ... + 2453.

It is an arithmetic number, because the mean of its divisors is an integer number (322260).

2^1921281 is an apocalyptic number.

It is an amenable number.

1921281 is a deficient number, since it is larger than the sum of its proper divisors (656799).

1921281 is a wasteful number, since it uses less digits than its factorization.

1921281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4095.

The product of its digits is 288, while the sum is 24.

The square root of 1921281 is about 1386.1028100397. The cubic root of 1921281 is about 124.3169355156.

The spelling of 1921281 in words is "one million, nine hundred twenty-one thousand, two hundred eighty-one".